This invention directs to Continuous Adjustable 3Deeps Filter spectacles for viewing 2D movies as 3D movies. Previously, related patent applications for Continuous Adjustable 3Deeps Filter spectacles have been disclosed that use electronically controlled variable tint materials for fabrication of the right and left lenses of the viewing spectacles. Generally, electronically controlled variable tint materials change the light transmission properties of the material in response to voltage applied across the material, and include but are not limited to electrochromic devices, suspended particle devices, and polymer dispersed liquid crystal devices. Such material provides precise electronic control over the amount of light transmission.
3Deeps spectacles adjust the optical properties so that the left and right lenses of the 3Deeps spectacles take on one of 3 states in synchronization to lateral motion occurring within the movie; a clear-clear state (clear left lens and clear right lens) when there is no lateral motion in successive frames of the motion picture; a clear-darkened state when there is left-to-right lateral motion in successive frame of the motion picture; and, a darkened-clear state when there is right-to-left lateral motion in successive frames of the motion picture.
We note that ‘clear’ is a relative term and even ‘clear’ glass will block a small percentage of light transmission. A clear lens is then one that transmits almost all light through the material.
Continuous Adjustable 3Deeps Filter spectacles are improved 3Deeps spectacles in that the darkened state continuously changes to take an optical density to provide the maximum Pulfrich stereoscopic 3D illusion optimized for (a) the speed and direction of lateral motion, and (b) the transition time of the electrochromic material from which the lenses are fabricated.
The problem addressed by the preferred embodiment of this invention is that of slow transition time when transitioning between different optical densities of the lenses of the Continuous Adjustable 3Deeps Filter spectacles. Optimal control of Continuous Adjustable 3Deeps Filter spectacles is achieved by adjusting the right- and left-lenses to the optimal optical density synchronized to maximize the 3D effect of the Pulfrich illusion between frames of the motion picture with respect to the transition time properties of the electrochromic material. As an example, a movie that is shown on a 100 Hz digital TV may require as many as 100 different optical density controlled lens transitions per second to optimally synchronize to the speed and direction of lateral motion in the motion picture. Most often the transitions in synchronization to the movie are small minor adjustments to the optical density of the lens that can be accomplished in the allotted time. A problem arises when 3Deeps Filter spectacles are fabricated from electronically controlled variable tint materials that are incapable of the ‘fast’ transition times that are sometimes required as for instance between scene changes. While electronically controlled variable tint materials may be able to achieve fast transitions from one optical density state to another optical density state that are ‘near’ or ‘close’ to each other, it may be incapable of transition between optical density states that are far apart. However, faster transition times using any electronically controlled variable tint material can be achieved by the simple expedient of using 2 or more layers—or multi-layers—of such material. Using multiple layers of material does result in a darker clear state, but the difference is minimal and barely perceptible, so the tradeoff between a slightly darker clear state and faster transition time is considered and warranted.
Another problem relates to the ‘cycle life’ (number of clear-dark cycles before failure) of some optoelectronic materials that may be limited. The ‘cycle life’ may be increased by using multiple layers of optoelectronic materials since the electric potential applied to the material to achieve a target optical density will be for a shorter period of time.
Another problem addressed by an alternate embodiment of this invention is that different methods of 3D require distinct viewing spectacles. However, with electronically controlled viewing spectacles, a single viewing spectacle can be switch selectable for different optical effects. For instance, to view a 3D movie that uses the anaglyph method to achieve 3D stereoscopy requires use of a different pair of spectacles (red-blue lenses) than that used for 3Deeps viewing. Other preferred embodiments of the invention relate to multi-use of the spectacles. The use of multi-layers of electronically controlled variable tint materials where different layers relate to different viewing methods, allow a single spectacle to be selectable to achieve different optical effects. For instance, while one or more layers of electronically controlled variable tint materials may be used for Continuous Adjustable 3Deeps Filter spectacles, another layer of materials may be used for anaglyph 3D spectacles. This would extend the use of a single pair spectacles so it can be selectively used for either Continuous Adjustable 3Deeps Filter spectacles viewing of 2D filmed movies or for anaglyph viewing of 3D filmed movies. It would also allow switching within any motion picture between 2D and 3D for a specific method, and/or switching within any motion picture between different methods of 3D. Till now a 3D motion picture may have been filmed in its entirety as anaglyph. With this invention the motion picture could have been filmed in part 2D with the multi-layer specs then set by signalization to a clear-clear state, and another part of the motion picture could have been filmed in 3D anaglyph with the multi-layer spectacles then set by signalization to a red-blue state. In another embodiment the picture may be filmed in part in 2D and 3D anaglyph, and shown to viewers in 2D, 3D using 3Deeps spectacle, and 3D anaglyph with the spectacles set accordingly.